Automatic electric switch.



S. S. STAHL.

AUoMAIC ELECTRIC SWITCH,

APPLICATION FILED NOV. 27,1915. l 1 190 032. PantedJu1y4,191.

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AUTOMUC ELECTRIC SVHTCH.

APPLucAlloN mw Nov.27, w15.

2 SHEETS-'SHEET 2.

Patented July 4, 1916.

ATTORNEYS 'y other' range'to open or close the swit h.

SIDNEY S. STAHL, OF CONNELLSVILLE, PENNSYLVANIA.

AUTOMATIC ELECTRIC SWITCI-T Specification of Letters Patent.

Patented July 4, 1916.

Application filed November 27, 1915. Serial No. 63,865.

To all whom it ymay concern Be it known that I, SIDNEY S. STAriL, a citizen of the United States, and a resident of Connellsvilie, in the county of Fayette and State of Pennsylvania, have inventeda new and Improved Automatic- Electric Switch, of which the following'is a full, clear, and eXact description.

This invention relates to automatic electrict switches of that general type disclosed in United States Letters Patent 1,141,847, granted to me on the first day of June, 1915, and wherein the movable element or elements of the switch are adapted to be automatically opened or closed quickly and positively so that danger of arcing is avoided when certain predetermined conditionsof pressure acting on the pressure responsive device exist, the invention being especially adapted for pumping systems whereby the switch controls operation of an electric motor for driving the pump so that the pump will be stopped whenthe iuid deliveredby the pump has reached a predetermined high pressure, and the motor will be automatically `started wlienithe fluid is lowered to a predetermined low pressure.

The invention has for its general obJects to improve and simplify the construction and operation of apparatus of the character referred to so as to be reliable and -efficient ,in use, comparatively simple and inexpen- Vof the contacts by arcing.

A more specific object of the invention is the provision of an operating means for an electric switch, which operating means includes a swinging m which is connected by flexible elements with the blade or blades of the switches, and by means of a novel arrangement of spring means the said arm after moving slightly beyond a dead center position is quickly thrown to positively jerk the switch open or force the same closed by a hammer blow.

' Still' another object ofthe invention is theprovision of novel connecting means between the pressure responsive ldevice of the system and the arm to which the movable element of the. switch is connected, whereby the arm moves through a certain range by reason of thel pressure responsive device and thenUoperatesV independently throu h anlV ith such objects in view, and others which will appear as the description proceeds, the invention comprises various novel features of construction and arrangement of parts which will be set forth with particularity in the following description and claims appended hereto.

In the accompanying drawing which illustrates one embodiment of the invention and wherein similar characters of reference indicate corresponding parts in all the views, Figure 1 is a front view of the automatically operated switch and pressure responsive device connected therewith; Fig. 2 is an enlarged front view of the switch with a portion in section; Fig. 3 is a front view of the movable element of the switch; Fig. 4 is an enlarged side view of the switch and operating mechanism therefor; Figs. 5 and 6 show different positions of the parts of the operating mechanism; and Fig. 7 is a detail view of a modified form of spring means for the actuating arm connected with the movable element of the switch.

In the present instance the invention is shown in connection with a pressure responsive device of a pump system, the pump of which is driven by an electric motor controlled by the switch, but it is to be understood that other means than a pressure responsive device may serve as the actuating agency.

Referring to the drawing, A designates an electric switch for controlling a motor circuit, B the means for operating the movable element of the switch, and C the pressure responsive device which controls the action of the mechanism B.

The switch and operating mechanism therefor are mounted on a back plate 1 and a shelf 2, respectively, which shelf is fastened to the back plate. The pressure responsive device C is suitably arranged adjacent to the switch and its operating means, and in the present instance it is located under the latter. This pressure responsive device comprises a chambered body 2 whicl has e diaphragm 3 which is subjected to p fessure in the delivery pipe 4 of a pump. On the ton of the diaphragm bears a plunger which is connected at 6 with a weighted lever i' fulcrumed at 8, and connected with this lever is a link 9 which has a turnbuckle 10 whereby the effective length of the link mai7 be changed.

The switch A comprises a porcelain base 11 which has a set of lower spring jaw contacts 12 and 13 to which the supply wires 14 and 15 are connected, and engageable with these contacts are switch blades 16 and 17 that are hinged at their upper ends on posts or contacts 18 and 19, that in turn connect with fuse plugs 2() and 2l screwed into sockets 22 and 23 in the base, and these fuse plugs are in turn connected with the wires 24 and 25 which lead to a motor for driving a pump that forces fluid through the pipe 4. The blades 16 and 17 are 'lastened to a cross bar 2G o't insulating material. The upper extremities of the blades 1G and 17 have laterally extending lugs 27 which are adapted to engage over the top of the contacts or posts 1S and 19 to limitthe outward throw or opening movement of the switch blades, which latter, connected together by the bar 2G, form the movable element of the switch. The supporting posts 18 and 19 project horizontally beyond the ends of the contacts 12 and 13 and the pivots 2S are so located that if the switch element hangs by gravity, the blades will not n'iake contact with the spring jaw contacts .l2 and 13, so that the switch must be closed by a positive force.

The operating means Ii for the movable element of the switch is mounted on the shelf 2 and includes an arm 29 which swings forwardly and backwardly across a vertical line passing through the axis on which the arm swings, and the upper portion of this arm 29 is connected by a pair of chains or equivalent flexible elements 30 with the cross bar 2G of the movable element of the switch, so that these chains will jerk the movable element of the switch to open position, this opening being effected quickly so that an arc will not spring between the contacts of the switch. On the upper extremity of the arm 29 is a horizontal bar 31 of insulation which serves as a hammer to impart a blow to the bar 26 of the movable element of the switch when the latter is in open position, so that the blow will force the said element to closed position, and furthermore, this piece of insulation 31 acts as a barrier between the electrically charged parts of the switch and the arm 29. The arm 29 has a longitudinal slot 32 whereby side members 33 are formed, and these side members are provided with journals 34 which are mounted in bearings 35 fastened to the top of the' shelf 2. One of the journals 34 is somewhat longer than the other and rigid thereon` is a short arm 3G that has a slot 37 to provide spaced lugs 3S and 39. Loosely mounted on the long journal 34 is a lever 40 which is hingedly connected at 4l with the link 9, and carried by this lever is a pin or lug 42 which is disposed in the recess 37, so that by swinging the arm 40 upwardly the pin will engage the lug 38 and move the arm 39 from the right to the left, Fig. 4, while a downward movement of the lever 40 will cause the pin 42 to engage the lug 3 9 and move the arm. to the right from the position shown in Fig. 6. The movement of the arm 39 is limited by lugs 43 projecting from the side thereof and engageable with upwardly extending ears 44 and 45 on the bearings The arm after it passes in either direction beyond a vertical dead center line is caused quickly to complete its movement for the purpose of opening or closing the switch suddenly. This means comprises an extensible belt formed by a helical spring 4G which has its ends 47 connected together, and this endless belt passes around a pulley 48 carried by the arm 39, and a pulley 49 which is mounted in a bracket bearing 50 which is fastened to the under side of the bracket 2. The endless belt passes through a slot 51 in the bracket 2 and extendsinto the slot 32 of the arm 29. This spring is of greatest length when the arm 29 is in the vertical dead center position with the pulley 48 vertically over the pulley 49, and as soon as the arm moves to one side or the other of a'dead center position the spring contracts and quickly throws the arm to the limit of its movement. In Fig. 4 the spring or endless 9 extensible belt 4G is contracted, but in Fig. 5 it is extended, and under a tension which, as the arm 39 moves to the left beyond its dead center position, will throw the arm to the position shown in Fig. 6. This same action takes place as the arm 29 moves to the right from the position shown in Fig. 6 to the position shown in Fig. 5, when the spring will contract and throw the arm 29 quickly to the position shown in Fig. 4. Instead of using a single spring, as shown in Fig. 4, two springs 52 may be used, as shown in Fig. 7.

From the foregoing description taken in connection with the accompanying drawing, the advantages of the construction and method of operation will be readily understood by those skilled in the art to which the invention appertains, and while I have described the principle of operation, together with the device which I now consider to be the best en'ibodiment thereof, I desire to have it understood that the device shown is merely illustrative and that such changes may bie iliade when desired as fall within the scope of the appended claims.

Having thus described my invention, I claim as new and desire to secure byI Letters Patent:

1. The combination of a switch including acontaet element movable to and from closed circuit position, an arm movable in one direction to impart a blow to the movable element to throw the same to closed circuit position, a flexible member connecting the arm with the said movable element f or jerking the latter to open circuit position, a device for initially moving the arm to a predeteimineil position, and means for quickly moving the arm in the same direction from spcct to the element as to impart a blow /lll thereto and Amove the samein 'the opposite ldirection, and quickly acting,r A:means asso- 'ciated with and operatingf the arm'.

3. The comliination of an electric switch inclu-ding a. movableelement, a swingingv arm haviigjr its outer end movable in the path of the saidj movable element for imparting a hammer blow thereto, a flexible connection between the arm and said element for movingtlie same in a direction .opposite from that due to the hammer blow, an actuator, a lost motion connection betweenl the actuator and arm, whereby the actuatorinoves the arm initially in both directions,I and means energized duringr the initial movement of the arm and active ai' ter the arm reaches a ln'mleterlnined position for suddenlycompleting,r the movement of the arm. 'V

4. lhe combination of an electric switch including a movableelement, a swinging arm havin-g its outer end movable in tlle path of the said movable element for imparting a hammer blow thereto, a flexible cpnnection between the arm and said le muentor moving the same in a direction' bpposite fromv is pivoted, a. contact disposed nmler the post and so arranged that tlleu'iovable coiihwt will not engage therewith when hangingV loosely, a meu/alile arm arranged to strike the said element'to throwfthesame to closed circuit position, a -li-.xiblle-member connecting the arm and element for movi'ngthe latter to open circuit position, means for moving;r the'armfto a predetermined posi- Coies et this potent may be obtained for tion qnicldy continuing the movement of the arm from such position. n

(i. The combination of a switch including a movable, element, an arm for moving the element to and from closed circuit position, a flexible connection between the arm and element, a supporting means for the arm, an actuator for moving the arm to a predetermined position, an endless spring element `connected with the' arm and extending beyond the axis on which the arm swings. means with which the spring engages ai a point beyond thesaid axis, whereby the spring extends as the arm moves to a dead center position and contracts as tlnl arm passes beyond such position, whereby lhl latter part of the movement of the arm is accelerated.

7. The combinationof a switch ini-india,r a movable element, a swinging arm arranged to move the said element to and l'rom closed circuit position, a supporting structuuon Y which the arm is fulcrumed, a pulley moan(- ed on the arm,`a pulley on the'structnre at the side of the fulcruni opposite [rom the first-mentioned pulley, an endless helical Y. spring' passing'around the pulleys, whereby e spring extends during the movement of the arm in either direction until the arm is in a dead center position, when' the spring contracts to complete the'movement of the arm,.and an actuator united by lost motion connection with the said arm for imparting an initial movement thereto.

8; The eombinationof a switch including a movable Contact element, a member on which the vupper end of the element is fulcrun'ied, a contact under the member for engagement by the said element for closinpr the circuit, and means on the said element. and cngageable with the said member for limiting!y the opening movement of the element, with `an operating mechanism Aineluding'a. member arranged to impart a blow to the said movable element for throwing the same to closed circuit position and attached to the element' by a flexible connection for jerking the said element to open circuit position.

ln'testimony whereof I have signed my name to this slwciication in the presence of two subscribing witnesses. v

y sinNnY STAI-1L. Witnesses:

y J. Fjllaiunson,

lt. M.. HALL,

ave cents each, by addressing the "Commissioner of Patents wasmngm, n. c."

and means for automatically and` lil() 

